The U.S. Department of Defense this week awarded a multi-million dollar contract to provide more than a thousand cluster bombs to Saudi Arabia, despite a growing international pressure to halt their use.

Textron Defense Systems was on Tuesday granted a contract modification increasing the contract’s total worth to $641 million for the production of 1,300 cluster bomb units. More than half of that amount — $410 million — comes from foreign military sales (FMS) funds on the behalf of the Kingdom of Saudi Arabia. Of that full amount, $230 million was awarded last year to “meet an urgent Saudi requirement for 328 units,” the Pentagon told ThinkProgress.

Designed for use in attacking tank formations and other massed armor vehicles, cluster bombs are named so for their ability to launch several submunitions while in flight, spreading the amount of damage they are able to do. Textron Systems’ VP of Communications Stephen Green assured Reuters that the weapons being provided — the CBU-105, also known as a Sensor Fuzed Weapon — meet Pentagon standards when it comes to cluster bombs. Specifically, Department of Defense regulations require that any cluster munition purchased by or through the U.S. military have no more than one percent of the submunitions the bomb launches remain unexploded once they reach the ground.

But that very need for DOD’s regulation highlights the dangers that cluster bombs’ unexploded ordinance has proven to be globally. The Cluster Munitions Campaign in its 2012 report identified 17,194 cluster munition casualties in 30 countries through the end of 2011, though the actual number may be far higher. Militaries and governments have historically been loathe to turn over comprehensive data on the use of cluster weapons and their unexplored ordinance for full and accurate reporting, leaving the potential for up to 20,000 to 54,000 casualties worldwide.

The variation of cluster bomb that the U.S. is providing Saudi Arabia has only been used in combat once: during the 2003 invasion of Iraq. 88 CBU-105s rained down on Iraq in the three weeks between March 20 and April 9. At that time, the bombs were hailed as a possible huge step forward in increasing the safety of such munitions. Since then, activists have reported finding more duds than would be allowed under the “less than 1 percent” rule currently in place, finding unexploded submunitions strewn throughout the area near Mosul, Iraq.

“We are disappointed with the US decision to export cluster bombs to Saudi Arabia as both countries acknowledge the negative humanitarian impact of these weapons on civilians,” said Sarah Blakemore, director of the Cluster Munition Coalition (CMC), said in a statement released on Thursday. The United States and Saudi Arabia alike both voted in favor of a U.N. General Assembly resolution condemning Syria’s use of cluster munitions against its civilian population.

The Obama administration in fact has often condemned the use of cluster bombs in extremely strong terms, as when then-Secretary of State Hillary Clinton shamed Libyan President Moamar Qaddafi’s use of the weapons during that country’s 2011 civil war. Despite that, the United States has refused to sign onto a global treaty governing the use of the weapons — the Convention on Cluster Munitions — despite more than 100 other countries having done so. And despite the growing stigma surrounding their use, the U.S. continues to sell the munitions to not only Saudi Arabia, but also Taiwan, India, and South Korea.

US Department of Defence has authorised $641m worth of cluster bombs to be sent to Saudi Arabia: here.